Water sprinklers are commonly used to deliver water to a spray area. Water sprinklers come in many forms including stationary water sprinklers and oscillating water sprinklers. Oscillating water sprinklers include a spray tube or other spray member that oscillates back and forth in order to deliver water to a greater area than would otherwise be possible if the spray member were fixed. Water flow provided to the oscillating sprinkler is typically used to drive a water motor which, in turn, drives the spray member in a repeating manner. When the spray member is driven to a first user defined oscillation point, the direction of the water motor drive is reversed. This change in drive direction reverses the direction of travel of the spray member. The spray member is then driven to a second user defined oscillation point where the drive direction of the water motor is again reversed, thus reversing the direction of travel of the spray member. This oscillating spray pattern continues as long as a flow of water is supplied to the sprinkler.
Various methods have been employed in past sprinklers to oscillate a spray tube. For example, sprinklers utilizing crank style motors oscillate the spray tube using a rocker arm and linkage connected to the crank. User defined stop points of the spray tube are adjusted by turning a knob, which effectively varies the length of the rocker arm. These crank style motors rotate in only one direction, but a significant lag time is experienced between directional changes of the spray tube. One type of motor that addresses this lag time issue is the rotary motor, which reverses direction. With rotary motors, the typical method of switching direction on a reversing water motor is to use the motor's power to load a spring or combination of springs. The energy of such the spring is released at a given moment in order to move a trip plate and reverse direction of the gear train. One problem with this arrangement is that more and more power is required by the motor as the spring is loaded. Another problem with this arrangement is that the springs often work like sea-saws and, just before they are released, they cross-over a balanced point and have a high potential to end up balanced in the center, pushing on the trip plates equally, and thus leaving the actual switch mechanism in an in-between position. Accordingly, it would be advantageous to provide a mechanism for switching the direction of a water motor which has relatively little lag time, is relatively simple in operation, and is durable with a long life expectancy.
In typical oscillating sprinklers the motor is operably connected to the spray tube such that operation of the motor results in oscillation of the spray tube. However, the spray tube or motor may be easily damaged by over-rotation of the spray tube relative to the motor. Accordingly, it would be desirable to include torque relief between the motor and the spray tube in an oscillating sprinkler. It would be further desirable if such torque relief could be provided with a mechanism that is relatively simply and easy to install in the sprinkler. It would also be desirable if such torque relieve could be provided in a manner that facilitates proper assembly of the spray tube including proper orientation of a spray coverage adjustment mechanism on the sprinkler.
Another problem with traditional oscillating sprinklers is that the adjustment mechanisms used to select a desired spray coverage area can be confusing. For example, with many sprinklers, a trip lever external to the water motor is mechanically and automatically pushed in order to bring about a reverse in direction of the spray tube at a user defined position. This has been accomplished by attaching an adjusting device onto the spray tube and allowing the adjusting device to rotate with the spray tube. The standard convention for this setup is to create a single lever area on each adjusting device and a stationary indicator on the sprinkler motor or base. However, these adjustment mechanisms tend to be confusing to users wishing to change the spray area covered by the sprinkler. For example, in order to increase water coverage to the right, the user must move the left adjusting lever further to the left. This arrangement often seems counter-intuitive to the user, as the user's inclination is typically to move the lever to the right in order to increase spray coverage to the right. Accordingly, it would be advantageous to provide a mechanism for adjusting the desired coverage area on an oscillating sprinkler that can readily understood by the user.